CRANIAL CAPACITY — DIAMETER OF NUCLEUS 163 



For the cranial capacity expressed in cc. Donaldson ('12), 

 the formula for sexes combined is 



Cranial capacity in cc. = 



1.02 log Bd. wt. - 0.00027 Bd. wt. - 0.596 (10) 

 [80 < Bd. wt. < 300] 



Spinal Cord Weight ok Body Weight (Donaldson, '09) 



Spinal cord wt. (sexes combined) = 



0.585 log (Bd. wt. +21) - 0.795 (11) 



In the female the spinal cord is about 2 per cent heavier than 

 in the male, therefore when using formula (11) the values ob- 

 tained require to be increased by 1 per cent to represent the 

 weight of the spinal cord in the female and to be diminished by 

 1 per cent to represent its weight in the male. By using this 

 procedure, the data on the weights of the spinal cord in table 68 

 have been obtained. 



Diameter of Second Cervical Spinal Ganglion Cell Nucleus on 

 Diameter op Cell Body (Hatai, '07b) 



Correlation between diameter of cell body and diameter of 

 nucleus in n — in spinal ganglion cells of second cervical nerve. 



Diameter of nucleus in n = 



12.2939 [ 1.0252 + 0.3564^ - 0.0758 (j\* j (12) 



where x is the diameter of the cell in n and 1 is a half range of the 

 variates. 



